Add support of stm32f103c6 devices

[hlyi]

Add support of DAPLink device ( new target daplink_f103c6) from Aliexpress.

Add option to ignore LEDs: LED_ACT_DISABLE, LED_RUN_DISABLE, LED_CON_DISABL for devices that do have all three LEDs.

Add option LED_CON_INVERT to inverse polarity of CON LED.